Gaya APA

Cunningham, F, G. et al (2010). WILLIAMS OBSTETRICS VOL 2 (23rd edition). United states of America: The McGraw-Hill Companies.

Gaya MLA

Cunningham, F., Gary. et al. "WILLIAMS OBSTETRICS VOL 2". 23rd edition United states of America: The McGraw-Hill Companies, 2010. Text.